#include<bits/stdc++.h> using namespace std; bool s(int x) { if(x < 2){ return false; } if(x == 2){ return true; } if(x % 2 == 0){ return false; } for(int k = 3; k <= sqrt(x); k += 2) { if(x % k == 0){ return false; } } return true; } int p(int x) { int r = 0; while(x > 0) { r = r * 10 + x % 10; x /= 10; } return r; } int main() { int M, N; cin >> M >> N; int a[1001] = {0}; int c = 0; for(int i = M; i <= N; i++) { if(s(i)) { int r = p(i); if(s(r)) { a[c++] = i; } } } if(c == 0){ cout<<"NO" << endl; }else{ for(int i = 0; i < c; i++) { if(i > 0){ cout<< ","; } cout<<a[i]; } cout<<endl; } return 0; }